﻿class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {

        int m = obstacleGrid.size();
        int n = obstacleGrid[0].size();

        vector<vector<int>> dp(m + 1, vector<int>(n + 1, 0)); // 创建⼀个 dp表

        dp[0][1] = 1; // 初始化

        // 填表
        for (int i = 1; i <= m; i++) // 从上往下
            for (int j = 1; j <= n; j++) // 从左往右
                if (obstacleGrid[i - 1][j - 1] != 1)
                    dp[i][j] = dp[i - 1][j] + dp[i][j - 1];

        // 返回结果    
        return dp[m][n];
    }
};